Sprayer comprising detection system for early power-off

ABSTRACT

A sprayer includes: a container; a passage including a transparent window, a first opening, a second opening and a resonator, wherein when liquid in the container is passed through the resonator via the first opening, the liquid is emitted as a gas via the second opening; and a removable detection unit disposed outside of the passage. The removable detection unit includes: a light source for illuminating the gas in the passage; an optical sensor disposed to detect a parameter of light reflected by the gas; and a processor coupled to the optical sensor for stopping the resonator from generating the gas when the parameter is below a threshold. The passage further includes a cavity disposed on a bottom surface of the passage in front of the optical sensor, wherein when the gas in the passage contacts the bottom surface, resultant water vapour will enter the cavity.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.17/144,080, filed on Jan. 7, 2021, which claims the benefit of U.S.Provisional Application No. 62/963,189, filed on Jan. 20, 2020. Thecontents of these applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to sprayers, and more particularly, toa detection system for a sprayer which uses a light-sensitive sensor todetect an average intensity of a gas emitted by an internal resonator ofthe sprayer in order to initiate power-off of the resonator.

2. Description of the Prior Art

In a sprayer, a liquid container holds liquid to be vaporized. Thesprayer further contains an ultrasonic resonator, which is disposed in alower part of the liquid container. A standard implementation of theultrasonic resonator is a fine mesh containing a plurality of tinyholes. The liquid passes through the tiny holes while the fine meshresonates at a high frequency (such as ultrasonic) , which causes theliquid to be emitted as a gas. When little or no liquid is being passedthrough the mesh, the ultrasonic resonator is at risk of damage. Priorart technologies therefore detect the absence of liquid in the liquidcontainer, or detect when liquid levels are low, and power-off theresonator according to the detection.

A conventional technique for determining a low or zero level of liquidin the container is to dispose two separate electrodes on the mesh. Whenliquid levels are sufficient to cover the mesh then there will be aconnection formed between the electrodes, i.e. the electrodes areconductive. When liquid levels are too low or empty such that no liquidor insufficient liquid covers the mesh, the electrodes will not beconductive.

One issue that exists in the prior art is that, even when there is noliquid in the container, there may be bubbles left over from theresonated liquid which cover the mesh. This results in the electrodesbeing conductive although the liquid levels are not sufficient for theultrasonic resonator to generate a gas output. The resonator willtherefore not be powered off even though there is no liquid in thecontainer, meaning the resonator will be damaged.

SUMMARY OF THE INVENTION

This in mind, it is an objective of the present invention to provide asystem and method for a diffuser that can perform early detection of lowliquid levels in the diffuser by detecting an intensity of the gasoutput.

This is achieved by a sprayer comprising a removable detection unit fordetermining when a liquid level of the sprayer falls below a specificlevel. The sprayer comprises: a container arranged to contain liquid; apassage comprising a transparent window, a first opening, a secondopening and a resonator, wherein when the liquid in the container ispassed through the resonator via the first opening, the liquid isemitted as a gas via the second opening; and a removable detection unitdisposed outside of the passage. The removable detection unit comprises:a light source disposed to emit light through the light transparentwindow for illuminating the gas in the passage such that the gas willreflect the emitted light; an optical sensor disposed to detect aparameter of the reflected light through the transparent window; and aprocessor coupled to the optical sensor for stopping the resonator fromgenerating the gas when the parameter of the reflected light is below afirst threshold corresponding to the specific level. The passage furthercomprises a cavity disposed on a bottom surface of the passage in frontof the optical sensor of the removable detection unit. When the gas inthe passage contacts the bottom surface, resultant water vapour willenter the cavity.

When the detection unit is removable, the detection unit comprises afirst contact plug and a second contact plug, the sprayer comprises athird contact plug and a fourth contact plug, the switch is coupled tothe processor via the second contact plug and the fourth contact plug,and the resonator is coupled to the processor via the first contact plugand the third contact plug. The detection unit further comprises atransparent window disposed opposite the transparent window of thepassage. The container may also be removable.

The light source may be an LED positioned next to the optical sensor,and may emit infrared light. The optical sensor may be a CMOS imagesensor, a CCD image sensor or a photodetector. The detected parametermay correspond to an average intensity of particles in the gas, and/ormay be directly proportional to a liquid level within the sprayer. Theoptical sensor may be arranged to sense light of a specific wavelengthor to sense light of a range of wavelengths.

The removable detection unit comprises a power supply for providingpower to the processor, the optical sensor and the light source, and thesprayer further comprises a switch for powering on or powering off thesprayer, wherein the switch is coupled to the processor. The resonatoris coupled to the power source via the processor.

The processor can further compare the parameter of the reflected lightwith a second threshold, wherein the second threshold corresponds to alow liquid level within the container, and the first thresholdcorresponds to a zero liquid level within the container. When theparameter of the reflected light is below the second threshold and abovethe first threshold, the sprayer generates a signal. The signal may be alight signal or an audio signal. The second threshold can be adjustedautomatically by the processor, or adjusted by a user.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a detection unit attached to a sprayer accordingto a first exemplary embodiment of the present invention.

FIG. 2 is a diagram of the detection unit attached to a sprayeraccording to a second exemplary embodiment of the present invention.

FIG. 3 is a flowchart of a method according to an exemplary embodimentof the present invention.

FIG. 4 is a diagram of the detection unit attached to a sprayeraccording to a third exemplary embodiment of the present invention.

DETAILED DESCRIPTION

The present invention provides a detection unit for a sprayer, whichuses a particle density of the emitted gas to determine when a liquidlevel of the sprayer is too low. This can prevent the erroneousdetermination of sufficient liquid levels which exists in the prior art.In addition, the present invention provides a more flexible designwherein the detection unit is attached to the outside of the sprayer ina removable manner.

The detection unit comprises a sensor, such as a CMOS sensor or a photodetector (e.g. a photodiode), as well as a light source. The lightsource emits light to illuminate the emitted gas, allowing the sensor todetect a density of particles according to the received light intensityof the light illuminated through the gas. As will be appreciated by oneskilled in the art, when a liquid level in the container falls below acertain level, the emitted gas will comprise very few particles and willtherefore have low density.

Insufficient liquid levels in the container can be determined by settinga threshold for particle density which corresponds to a number ofparticles emitted by the sprayer. A processor in the detection unitcoupled to the CMOS sensor can operate to control all functions of theCMOS sensor. By further coupling the processor to the resonator in awired or wireless manner, certain operations of the resonator such aspower-on/power-off can be controlled. In particular, this allows theprocessor to power-down the resonator when a density of particlesdetected in the emitted gas falls below a predetermined threshold,indicating that a liquid level within the container is below aparticular level.

Refer to FIG. 1, which is a diagram of a sprayer 100 according to afirst exemplary embodiment of the present invention. The sprayer 100comprises a container 110 and a body 120, wherein the container 110 isremovable from the body 120 and the container 110 has an opening 111 torelease the liquid.

The body 120 includes a passage 130 for the aerosol (gas) flow, and adetection unit 140 comprising a processor 141, a sensor 142 and a lightsource 143 assembled in a substrate 144. The passage 130 has an opening131 facing the opening 111 of the container 110 for receiving the liquidfrom the container 110. A resonator 132 is disposed in the opening 131to vaporize the liquid from the container 110 into gas. The light source143 illuminates the gas and the illuminated gas is reflected by thepassage 130 and detected by the sensor 142. The processor 141 receiveslight information (such as an intensity value) from the sensor 142,wherein the processor 141 may be a DSP, an MCU or any hardware capableof calculating digital or analog signals. The sensor 142 may be a CMOSimage sensor or a photodiode capable of detecting light emitted by thelight source 143. The light source 143 may be an LED or a Laser capableof emitting light to the passage 130.

A power source 145 provides power (current) to the substrate 144, andtherefore operates to power the processor 141, the sensor 142, and thelight source 143. The processor 141 is electrically coupled to thesensor 142, the light source 143 and the resonator 132 to controloperations of the sensor 142, the light source 143 and the resonator132.

A switch 146 maybe disposed on the outer surface of the sprayer 100 toallow a user to power-on/off the sprayer 100. In this case, the switch146 is also electrically coupled to the processor 141 so that, when auser powers-on or powers-off the sprayer 100, the processor 141 willturn on/off the sensor 142, the light source 143 and the resonator 132accordingly. As shown in FIG. 1, the processor 141 is also electricallycoupled to the resonator 132, allowing the processor 141 to directlypower-off the resonator 132 when a low or zero liquid level of thecontainer 110 is detected.

FIG. 2 illustrates a sprayer 200 according to a second exemplaryembodiment of the present invention, wherein both the detection unit 240and the container 110 are removable. As the processor 141 is disposed inthe detection unit 240 and therefore cannot be directly coupled to theresonator 132 which is in the body 120 of the sprayer 200, the body 120further includes contact pins 132 a (coupled to the resonator 132) and146 a (coupled to the switch 146), and the detection unit 240 furtherincludes contact pins 141 a and 141 b (coupled to the processor 141),enabling an electronic connection between the processor 141, theresonator 132 and the switch 146.

As illustrated in FIG. 1 and FIG. 2, the passage 130 includes a lighttransparent window 133 facing the sensor 142 and the light source 143 toallow light emitted by the light source 143 to pass through andilluminate the emitted gas, as well as allowing the sensor 142 to detectthe illuminated gas. When the detection unit 240 is removable as shownin FIG. 2, the detection unit 240 also comprises a light transparentwindow 147 facing the light transparent window 133.

By illuminating the emitted gas with the light source 143 and detectinglight information by the sensor 142, the average intensity of thereceived light from the sensor 142 can be calculated by the processor141, enabling the processor 141 to determine the average density of thegas. Although the invention is not restricted to detecting a particulargaseous suspension, the particles suspended in the emitted gas should belarge enough to influence the density of the gas when illuminated by thelight source.

When the gas is illuminated with the light source 143, the light will bereflected by the gas, with an amount/intensity of reflected lightaccording to the density of the gas. If the gas is very dense then thereflected light will be of a high intensity; as the density of the gasdecreases, so will the intensity of the reflected light. At least onethreshold corresponding to a specific intensity of reflected light(preferably a low intensity) is set. When the reflected light fallsbelow this threshold, it can be determined that the liquid level withinthe diffuser has become low enough such that an insufficient number ofparticles are emitted causing the gas to become less dense. At thispoint, the processor 141 can determine to power-off the resonator 132.

As different liquids will have different densities when emitted as agas, it is possible to set multiple thresholds corresponding todifferent liquids. In this case, the processor can be set to detect aparticular threshold corresponding to a particular liquid by being setin a particular mode. Furthermore, it is also possible to set multiplethresholds corresponding to different densities of a same gas. Asdetailed in the background, when there is a low level liquid in thecontainer 110, the resonator 132 can still emit a gas and therefore willnot be immediately damaged; when the liquid level in the container isalmost zero, the resonator 132 is in immediate danger of being damaged.By setting a first threshold corresponding to the first situation, andsetting a second threshold corresponding to the second situation, anintensity of the emitted gas falling below the first threshold can beused to inform a user that liquid in the container 110 should bereplaced, but will not result in immediate power-off of the resonator132.

In the above situation, the user may be informed that liquid levels inthe container 110 are getting low by emitting a sound or activating avisual indicator such as an LED 148, which is illustrated as positionedabove the switch 146, but is not limited therein. The LED 148 can becontrolled by the processor 141 upon receiving feedback from the sensor142.

As shown in FIG. 1, the container 110 is removable from the body 120 ofthe sprayer 100. As shown in FIG. 2, both the container 110 and thedetection unit 240 are removable from the body 120 of the sprayer 200.This allows for more flexibility in design. In both embodiments, theinternal surface of the passage 130 should not be highly reflective asthis will cause the reflected light intensity to give an erroneousresult with regards to the light intensity.

In both an operation mode where only one threshold is set and anoperation mode where multiple thresholds are set, the processor 141 willdirectly stop the resonator 132 from generating the gas when a parameterof the received light is below a threshold corresponding to a low liquidlevel meaning the resonator 132 is in imminent danger of being damaged.For example, the processor 141 determines if the intensity level of thereflected light received by the sensor 142 is lower than a threshold,and identifies the liquid level as being insufficient when the intensitylevel is lower than the threshold. The threshold may be able to bemanually adjusted by a user, or automatically adjusted when theprocessor receives the information of the liquid through a wiredconnection port (ex, USB) or wireless connection (ex, Bluetooth).

In addition, a further threshold corresponding to a change in the sensorsignal can be set, which indicates that the container 110 and/or thedetection unit 240 have been removed. In both cases, removal of thecorresponding unit will result in no gas or a significantly reducedamount of gas passing in front of the light transparent window 147 andsensor 142. This detection can be used to automatically power down thesprayer to save power or, in another embodiment, this detection canresult in a warning signal/sound indicating that components of thesprayer are not properly connected.

In one embodiment, the light source 143 is infrared (IR) light, as thiswill be invisible to a user and will therefore not influence or affectthe user in any negative way. In another embodiment, it is also possiblefor the light source 143 to comprise a plurality of light sources whichemit light of multiple wavelengths, and the sensor 142 may detectdifferent light intensity information corresponding to these differentwavelengths, which enables the processor 141 to analyze the dense of thegas more precisely. In one embodiment, ultrasound waves may be usedinstead of infrared waves.

A standard size of the particle which can be detected is 5 micrometers.In one embodiment, the detection unit 140/240 is only able to detect aspecific particle size. In another embodiment, the detection unit140/240 may be able to detect particles over a range of sizes. In thiscase, the sensor may be instructed as to which size particle is to bedetected, and a detection range of the sensor is set accordingly.

Once the resonator 132 is powered-off by the processor 141 so that nogas is emitted, the sensor 142 and the light source 143 may then bereset or powered-off correspondingly.

The above structure may also be applied to a system for detecting thecleanliness/purity of air. As is well-known, micro-particles such as 2.5and 5 are present in air which indicates pollution. The above embodimentcan thereby be applied to a system for testing the pollution index ofair.

Refer to FIG. 3, which is a flowchart detailing an operation of thesensor 143 and the processor 141 for the sprayer 100/200. Note that theflow is not limited to the steps detailed below; other steps maybeinserted, some steps maybe deleted, and the order of the steps may bechanged provided that the method detects a density of the emitted gasand uses that to control an operation of the sprayer.

The flow is as follows:

Step 300: Start. If light of multiple wavelengths is provided, go toStep 310; if light of a single wavelength is provided, go to Step 320.

Step 310: Light source mode selection.

Step 320: Continuous light excitation.

Step 330: Receive light signal.

Step 340: Is the received light signal above a starting threshold? Ifyes, go to Step 350; if no, return to Step 330.

Step 350: Find the maximum amplitude.

Step 360: Determine a specific percentage of the maximum amplitude. Isthe amount below a weak spray threshold? If yes, go to Step 370; if no,go back to Step 350.

Step 370: Shut down the sprayer.

Step 380: End.

The above procedure details a detection unit for a sprayer which canutilize particle density of an emitted gas to determine when a liquidlevel in the sprayer is low or zero. The detection unit can use thisdetection result to power-off the resonator, thereby preventing damageto the resonator.

One issue which can arise when the gas travels through the passage isthat water vapour will be formed at the points of contact with the innersurface of the passage. When this occurs in the area directly in frontof the sensor, the resultant water vapour may affect the visibility andtherefore sensitivity of the sensor, possibly resulting in erroneousdetection.

In order to maintain sensitivity of the sensor even when water vapour isformed within the passage, a sprayer 400 according to a third exemplaryembodiment is provided, as illustrated in FIG. 4. Same numerals are usedfor same components shown in FIG. 2 for the sake of brevity. As in theembodiment illustrated in FIG. 2, both the container 110 and thedetection unit 240 are removable; the body 120 therefore includes thecontact pin 132 a coupled to the resonator 132 and contact pin 146 acoupled to the switch 146, and the detection unit 240 includes contactpins 141 a and 141 b coupled to the processor 141, and the detectionunit 240 also comprises the light transparent window 147 facing thelight transparent window 133.

The difference between the embodiment illustrated in FIG. 4 and theembodiment illustrated in FIG. 2 is that the passage 130 includes acavity 135 formed on the bottom surface of the passage 130 andpositioned in front of the light transparent window 133. This cavity 135is also positioned directly below the opening 131. When the gas movesthrough the passage 130 as illustrated by the arrow ‘aerosol flow’,water vapour maybe formed on the bottom inner surface of the passage 130due to differences in the temperature of the gas and the surfacetemperature of the passage 130. The resultant water vapour may directlyform on the light transparent window 133, or at least form in the spacein front of the light transparent window 133, thereby reducing thesensitivity of the sensor 142.

By providing the cavity 135, any water vapour formed within the passage130 will drop into the cavity 135 due to gravity, and will therefore bebelow the bottom level of the light transparent window 133, so thesensor 142 can have an unobstructed view of the illuminated gas. Thismaintains the sensitivity of the sensor 142, such that the sprayer 400can accurately detect a particle density of the emitted gas and use saidparticle density to determine when a liquid level of the sprayer is toolow.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A sprayer comprising a detection unit fordetermining when a liquid level of the sprayer falls below a specificlevel, the sprayer comprising: a container arranged to contain liquid; apassage comprising a transparent window, a first opening, a secondopening and a resonator, wherein when the liquid in the container ispassed through the resonator via the first opening, the liquid isemitted as a gas via the second opening; and a removable detection unitdisposed outside of the passage and comprising: a light source disposedto emit light through the light transparent window for illuminating thegas in the passage such that the gas will reflect the emitted light; anoptical sensor disposed to detect a parameter of the reflected lightthrough the transparent window; and a processor coupled to the opticalsensor for stopping the resonator from generating the gas when theparameter of the reflected light is below a first thresholdcorresponding to the specific level; wherein the passage furthercomprises a cavity disposed on a bottom surface of the passage in frontof the optical sensor of the removable detection unit, wherein when thegas in the passage contacts the bottom surface, resultant water vapourwill enter the cavity.
 2. The sprayer of claim 1, wherein the detectionunit comprises a first contact plug and a second contact plug, thesprayer comprises a third contact plug and a fourth contact plug, theswitch is coupled to the processor via the second contact plug and thefourth contact plug, and the resonator is coupled to the processor viathe first contact plug and the third contact plug.
 3. The sprayer ofclaim 1, wherein the detection unit comprises a transparent windowdisposed opposite the transparent window of the passage.
 4. The sprayerof claim 1, wherein the light source is an LED and is positioned next tothe optical sensor.
 5. The sprayer of claim 4, wherein the LED emitsinfrared light.
 6. The sprayer of claim 1, wherein the container isremovable.
 7. The sprayer of claim 1, wherein the detection unitcomprises a power supply for providing power to the processor, theoptical sensor and the light source, and the sprayer further comprises aswitch for powering on or powering off the sprayer, wherein the switchis coupled to the processor.
 8. The sprayer of claim 7, wherein theresonator is coupled to the power source via the processor.
 9. Thesprayer of claim 1, wherein the optical sensor is a CMOS image sensor, aCCD image sensor or a photodetector.
 10. The sprayer of claim 1, whereinthe processor can further compare the parameter of the reflected lightwith a second threshold, the second threshold corresponds to a lowliquid level within the container, the first threshold corresponds to azero liquid level within the container, and when the parameter of thereflected light is below the second threshold and above the firstthreshold, the sprayer generates a signal.
 11. The sprayer of claim 10,wherein the signal is a light signal.
 12. The sprayer of claim 10,wherein the signal is an audio signal.
 13. The sprayer of claim 10,wherein the second threshold can be adjusted automatically by theprocessor, or adjusted by a user.
 14. The sprayer of claim 1, whereinthe parameter corresponds to an average intensity of particles in thegas.
 15. The sprayer of claim 1, wherein the parameter is directlyproportional to a liquid level within the sprayer.
 16. The sprayer ofclaim 1, wherein the optical sensor is arranged to sense light of aspecific wavelength.
 17. The sprayer of claim 1, wherein the opticalsensor is arranged to sense light of a range of wavelengths.